Biometric IBM ThinkPad T42

Fingerprint-scanning prototype

Common Topics

Review Last week I attended an IBM briefing, held at The Clink Museum near London Bridge. The Clink was an old Prison and the museum is full of gruesome memorabilia relating to the bad old days of sadistic incarceration. The reason that IBM chose this particular venue is because the theme of the evening was security, and what better place to talk about security than in a prison?

IBM had a lot to talk about when it came to security, but the most interesting part of the presentation was the announcement that the T-Series of ThinkPads were going to be equipped with biometric security in the shape of a fingerprint scanner. On display were two pre-production T42 notebooks, complete with the foresaid scanner, and while other journalists were busy scanning their fingertips, I was negotiating the release of one of the imprisoned notebooks. Thankfully the negotiations were successful, and a prototype T42, with integrated fingerprint scanner, was set free and shipped to the TrustedReviews office the next day.

So, sitting in front of me right now is a notebook very similar to the ThinkPad T42 that I reviewed a few weeks ago. However, just below the cursor keys is a slim, and very unobtrusive fingerprint scanner. IBM has chosen to go with a swipe-scanner rather than a touch-scanner, for a number of reasons. First and foremost is that a swipe-scanner provides better security. Because you have to drag your fingertip across the scanner, there is no way to "lift" a fingerprint from the surface. Your fingertips contain oil, which is why you leave fingerprints on surfaces when you touch them, and why cat burglars always wear gloves in the movies. With touch-scanners, you will leave a pretty accurate impression of your fingerprint on the surface of the scanner itself, and if someone really knows what they're doing, they could remove that print and use it to fool the scanner into thinking that they are you. The second reason for going with a swipe-scanner is that it can be far smaller than a touch-scanner, since it doesn't have to accommodate your whole fingertip. The third and final reason is that touch scanners have a habit of getting dirty, and need to be cleaned regularly to maintain an accurate read of your fingertip. Swipe-scanners can take a bit of getting used to, but once you get the hang of drawing your finger across the surface smoothly, you won't have a problem.

The capacitive sensor technology in the fingerprint scanner, senses the patterns of electrical resistance caused by the ridges and furrows in the fingertip. Multiple readings of the fingerprint are taken while it is slid across the surface of the scanner. All the readings are then combined to form an accurate image of the swiped finger.

When I first booted up this special ThinkPad T42, I was greeted with the "IBM Fingerprint Software" window. This is where you can configure the fingerprint scanner and enrol the fingers that you wish to use. The first thing I did was to enrol one of my fingers in the Power On security section. This would allow me to protect unauthorised booting of the notebook with a fingerprint instead of a password. When you enrol a finger, you have to scan it three times successfully. Once that is done, the software amalgamates all three images into a single image, to which it will compare any scans that it receives in the future.